Improvement in rotary valve and seat



E. L. WATKINS. Rotary Valve and Seat.

No. 218,348. Patented Aug. 5,1879.

N-PEI'ERS, PNOTO-UTNOGRAPHER, WASHINGTON, I)v C.

UNITED STATES PATENT OEEIoE.

EDWARD L. WATKINS, OF SAN ANTONIO, TEXAS.

IMPROVEMENT IN ROTARY VALVE AND SEAT.

Specification forming part of Letters Patent No. 218,348, dated August5, 1879; application filed May 12, 1879.

To all whom it may concern:

Be it known that I, EDWARD LANCASTER WATKINS, of San Antonio, in thecounty of Bexar and State of Texas, have invented a new and usefullinprovementin an Improved Rotary Valve and Seat, of which the followingis a specification.

Figure 1 is a vertical section of my improved steam chest and valve.Fig. 2 is a top view of the same, the valve-rod being shown incrosssection. Fig. 3 is a detail top view of the bottom of thesteam-chest. Fig. 4 is a detail top view of the valve shown in placeupon the bottom of the steam-chest, and part being broken away to showthe other port. Fig. 5 is a bottom view of the valve shown in place inthe steam-chest, and part being broken away to show the steam-inletport.

Similar letters of reference indicate corresponding parts.

The object of this invention is to furnish an improved rotary valve andseat for steam-cylinders which shall be simple in construction, reliablein operation, and easily regulated and controlled.

The invention consists in combining, with a valve-seat having fourports, a rotary valve having a curved opening and recess, as hereinafterdescribed.

A represents the steam-chest, which is made in circular or cylindricalform, and its lower head is attached to or formed upon thesteamcylinder. In the lower head of the steamchest A are formed twoports, a a leading to and opening into the said steam-cylinder at ornear its ends, and in the center of the said lower head is formed theexhaust-port a In the upper head of the steam-chest A is formed a portor hole, a, through which the steam is introduced from the boiler.

B is the valve, which is made in circular form and rests upon the innerside of the lower head of the steam-chest A. Through the valve B isformed an opening, 12 which is made in the form of a section of a ring,of a breadth equal to the length of the ports a a and of a length aboutequal to one-quarter of a circle. The opening b is made in such aposition as to come over the ports a a alternately as the valve Brotates upon its axis. In the lower side of the other half of the valveB is formed a recess, W, of a size nearly equal to a haltcircle. and ofsuch a depth that the exhauststeam can readily pass through it fromeither of the ports a a? to the exhaust-port of.

To the center of the valve B is attached the end of thevalve-rod G,which passes outthrough a stuffing-box, D, secured in a hole in thecenter of the outer head of the steam-chest A. To the outer part of thevalve-rod O is attached a small gear-wheel, E, to mesh into the gearingby which the said valve is driven.

The valve B is designed to be driven at such a speed as to make exactlyone revolution during each stroke and return of the cylinderpiston.

With this construction, when the valve B is driven at a uniform speed,the steam will be cut off at about half-stroke of the cylinderpistonbut, if desired, it may be so geared as to be driven at a variablespeed, and arranged to cut ofl steam at any desired point of the stroke.

Having thus described my invention, I claim as new and desire to secureby Letters Patent The valve-seat, having ports a a a a, in combinationwith rotary valve B, having the curved opening 11 and recess [1 as shownand described, whereby the valve is the only movable piece to supply andout off steam from the cylinder, constructed and arranged as shown anddescribed.

EDWARD LANCASTER WATKINS.

Witnesses A. M. OoHEN, T. B. WREN.

